Currently it does default to the current date and only allows one date for each entry. However, when you return to the service order edit page after adding time you can change the date if you would like.

Yes, I know, but I have to return to every service order every time I log time for several days, I have to put the date in the description, so I know what date to change it to. Not very convenient, and kind of defeats the purpose of being able to log time. Is this something that is planned to change?